Compositions for capstock applications

ABSTRACT

A thermoplastic polymer alloy compositions including a blend of polymers that each contribute beneficial properties to the compositions. The compositions exhibit characteristics desirable for outdoor applications such as weatherability, impact resistance and durability, while offering excellent surface appearance. The compositions are particularly suitable for decking applications and as capstock materials.

FIELD OF THE INVENTION

The present invention relates to a thermoplastic polymer alloycompositions including a blend of polymers that each contributebeneficial properties to the compositions. The compositions exhibitcharacteristics desirable for outdoor applications such asweatherability, impact resistance and durability, while offeringexcellent surface appearance. The compositions are particularly suitablefor decking applications and as capstock materials.

BACKGROUND OF THE INVENTION

Many different materials, for example, polymers such as polyvinylchloride (PVC), acrylonitrile/butadiene/styrene (ABS) and high impactpolystyrene (HIPS) exhibit desirable structural or mechanical propertieswhen formed into an article of manufacture. However, sometimes thesurface properties of such materials are lacking in one or more areas,for example scratch resistance, impact resistance and weatherability. Asa result, multi-layer compositions have been developed wherein an outerlayer or capstock has been bonded to a base material and covers apreviously exposed surface in order to provide sought-after performance.Such capstock layers are usually thinner than the base material.

Various polymers and polymer blends have been used as capstocks, see forexample U.S. Pat. Nos. 8,658,716, 8,034,441, 7,651,648, 7,338,706,6,773,821, 6,696,513, 6,555,245, 6,534,592, 5,318,737; U.S. PublicationNos. 2013/0303644, 2013/0317139, 2012/0128967, 2010/0330272,2009/0258208, 2008/0293837, 2007/0154689 2007/0092701; and InternationalApplication Nos. WO2014/018817.

Some documents, such as U.S. 2009/0258208, U.S. Pat. No. 6,555,245, andU.S. Pat. No. 6,773,821 describe a problem when using PVC as a capstocklayer. As stated in these documents, PVC sometimes cannot withstanddemanding environmental and outdoor UV exposure. In view of this,problems of present invention were to provide compositions, especiallycapstock compositions, that are easily processable, readily bondable toa substrate, weatherable, durable, impact resistant, mar and scratchresistant, and flame retardant.

SUMMARY OF THE INVENTION

The problems noted above and others are solved by the compositions ofthe present invention which comprise a blend of halogen-containingpolymers such as polyvinyl chloride, thermoplastic polyurethane and oneor more acrylic polymers.

One object of the invention is to provide a composition that can beapplied as a capstock material over a layer of a substrate material,often as a relatively thin layer, via melt processing, thereby forming acomposite.

Still another object of the present invention is to provide compositionsthat have excellent weatherability, impact resistance, durability,and/or desirable surface appearance.

Another object of the present invention is to provide capstockcompositions, that are easily processable and readily bondable to asubstrate.

An additional object of the present invention is to providecompositions, especially capstock compositions, that are mar and scratchresistant and/or flame retardant.

A further object of the present invention is to provide compositionsthat can be coextruded, crosshead extruded, or otherwise bonded to asubstrate with good bond strength.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and other features andadvantages will become apparent by reading the detailed description ofthe invention, taken together with the drawings, wherein:

FIG. 1 is a cross-sectional view of one embodiment of a compositecomprising a capstock material over a layer of a substrate material.

DETAILED DESCRIPTION OF THE INVENTION

The compositions of the present invention which are suitable, amongother uses as capstock materials, comprise a blend of halogen-containingpolymers, a thermoplastic polyurethane, and one or more, and preferablya plurality of different acrylic polymers. The compositions can alsoinclude other ingredients or additives, for example as described hereinbelow. As utilized herein the term polymer encompasses both hompolymersand copolymers of two or more different monomers.

Halogen Containing Polymers

The polymer compositions of the invention incorporate ahalogen-containing polymer therein. Examples of suitable halogencontaining polymers include, but are not limited to, polyvinyl chloride,polyvinyl fluoride, polyvinyl bromide, polyvinylidene chloride,chlorinated polyvinyl chloride, polyvinylidene fluoride andpolyvinylidene bromide. Chlorine containing vinyl polymers are preferredin one embodiment. Polyvinyl chloride is preferred in variousembodiments.

Halogen-containing polymers, offer the benefit of being inherently flameretardant due to polymer containing relatively high halogen content,such as 57 weight % chlorine in the case of PVC. Varioushalogen-containing polymers, such as PVC are also polar in nature withthe ionic bonds providing good chemical resistance against certainsolvents.

Halogen-containing polymers are available from many commercial sourcesunder various designations including, but not limited to, Oxyvinyl, asOXY 200, OXY 216S, OXY 500F, and as Oxy 225, Shintech as SE 800A, SE950A, SE 1100A, Formosa, Formolon 616K, Formolon 622R, and Formolon622F.

The halogen containing polymers can be present in compositions of theinvention in amounts which range generally from about 15 to about 60,desirably from about 20 to about 40 and preferably from about 25 toabout 35 parts by weight based on 100 total parts by weight of thecomposition.

Thermoplastic Polyurethane (TPU)

Thermoplastic polyurethanes are another polymer present in the blendcompositions of the present invention. Polyurethanes are generallyprepared by combining and reacting a polyol, generally a polyolcomponent of at least one hydroxyl terminated intermediate such as ahydroxyl terminated polyether, polyester, polycarbonate orpolycaprolactone, with a polyisocyanate. Polyamines are sometimesincluded in the reaction. The reaction can additionally include chainextenders and catalysts. Polyisocyanates include two or more isocyanategroups per molecule. Likewise, polyols include two or more hydroxylgroups per molecule.

In various embodiments, generally any type of TPU can be utilized andblends thereof, such as but not limited to ether and ester TPU grades.The thermoplastic polyurethanes used in the invention may be aliphaticor aromatic, or combinations thereof. In one preferred embodiment,polyurethanes prepared utilizing polyether polyols are preferred.Polyether TPU grades have the advantage of providing improved hydrolysisresistance, mildew resistance, and anti-microbial properties overpolyester TPU resin grades.

Thermoplastic Polyurethanes provide the benefit of achieving exceptionalabrasion resistance and chemical resistance. Thermoplastic polyurethanesalso are known to reduce the modulus of PVC without incorporatingplasticizers.

Polyurethanes are available from many commercial sources including, butnot limited to, A. Shulman, Bayer, BASF, Huntsman, Lubrizol, RTP, andTechmer and COIM under various designations. Suitable TPU grades arefrom BASF as Elastollan A1154D, Elastollan 1195A, and Elastollan 1190A,Bayer as Texin DP7-3041, Texin DP7-3018, Texin DP7-3006, Texin DP7-3007,Texin DP7-SUN 3006, and from Lubrizol as Estane 58213.

The polyurethanes can be present in compositions of the invention inamounts which range generally from about 1 to about 50, desirably fromabout 1 to about 40 and preferably from about 1 to about 25 parts byweight based on 100 total parts by weight of the composition.

Acrylic Polymers

The compositions of the present invention include at least one andpreferably a plurality of different acrylic polymers. Various differentacrylic polymers can be utilized including, but not limited to,polyacrylate-styrene-acrylonitrile, styrene-acrylonitrile, cross-linkedacrylonitrile and high molecular weight or ultra-high-molecular weightstyrene-acrylonitrile copolymer.

Polyacrylate-styrene-acrylonitrile (ASA) Copolymer

The compositions of the present invention also include apolyacrylate-styrene-acrylonitrile copolymer. ASA is typicallyclassified as a terpolymer which can be made by various methods as knownto those of ordinary skill in the art. For example, ASA can be made bygrafting SAN to an acrylate, for example a polybutylacrylate rubber, toform a SAN-soluble polybutylacrylate rubber.

Other acrylates can be utilized, such as alkyl (meth)acrylates havinggenerally from about 1 to about 8 carbon atoms, such as methyl(meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, orethylhexyl (meth)acrylate. When utilized herein, the term “(meth)” meansthat methyl group may be present or absent. Butyl (meth)acrylate ispreferred in one embodiment.

Styrene in the ASA refers to any vinyl aromatic monomer, including, butnot limited to styrene; alkyl styrene, such as alpha-methylstyrene; andring-alkylated styrenes, for example p-methylstyrene.

Acrylonitrile monomers include acrylonitrile and methacrylonitrile.

The acrylate content of the ASA ranges generally from about 10 to about60, desirably from about 30 to about 50 and preferably from about 35 toabout 45 parts per 100 parts by weight of the ASA. Further, the ASAtypically has a styrene content of from generally about 20 to about 50,desirably from about 25 to about 40 and preferably from about 25 toabout 30 parts per 100 parts by weight of the ASA. The ASA has anacrylonitrile content of from generally about 5 to about 35, desirablyfrom about 5 to about 30 and preferably from about 10 to about 20 partsper 100 parts by weight of the ASA.

Various grades of ASA are commercially available from sources such asBASF as LURAN™ SSE, Sabic as Geloy™ CR3020, and Galata Chemicals asRoyaltuf® 960A which is stated to include 60 percent polybutylacrylateand Royaltuf® 945A which is stated to include 45 percentpolybutylacrylate.

ASA provide the benefit of offering exceptional weathering and UVresistance particularly of dark colored articles.

The ASA can be present in compositions of the invention in amounts whichrange generally from about 10 to about 50, desirably from about 15 toabout 50 and preferably from about 15 to about 35 parts by weight basedon 100 total parts by weight of the composition.

Styrene Acrylonitrile (SAN) Copolymer

At least one styrene acrylonitrile copolymer is also present in thecompositions of the present invention. In some embodiments, two or more,three or more, etc., different types of SAN are present. SAN istypically classified as a copolymer, which is made by reactingacrylonitrile monomers and styrene monomers, see for example theacrylonitrile and styrene monomers defined hereinabove.

In one embodiment of the present invention, a so-called standard type ofSAN is utilized. SAN provides the benefit of a fusion promoter andprocess aid for PVC. SAN also provides the ability for dilution with ASAto control the rubber wt % content of the ASA. In a further embodimentof the present invention, the compositions include cross-linked SAN. Thecross-linked SAN is useful as a matting agent in various embodiments ofthe invention. The cross-linked SAN is a matting agent and is a mixtureof polystyrene and acrylonitrile-styrene copolymer, including astyrene-based matrix and cross-linked acrylonitrile-styrene copolymerwherein the mixture can include polystyrene in an amount of 20-30 weight% and acrylonitrile-styrene copolymer in an amount of about 70-80 weight%. In yet a further embodiment of the present invention, a relativelyhigh molecular weight styrene-acrylonitrile copolymer is utilized incompositions of the present invention. By high molecular weight it ismeant that the end copolymer has a molecular weight greater than 1million, desirably greater than 2 million, preferably greater than 3million weight average as measured by Gel Permeation Chromotography(GPC) using a suitable solvent and compared against Polystyrenestandards. By comparison, the standard grades of SAN include molecularweights below the lowest range of the high molecular weight SAN, i.e. 1million weight average or less and preferably below 500,000 weightaverage. High-molecular weight SAN can adjust the melt strength duringextrusion.

The SAN generally has an acrylonitrile content of preferably from about10 to about 50 parts by weight based on 100 parts by weight of the SAN.That said, the SAN styrene content ranges preferably from about 50 toabout 90 parts by weight based on 100 parts by weight of the SAN.

The SAN can be present in compositions of the invention in amounts whichrange generally from about 10 to about 50, desirably from about 10 toabout 40 and preferably from about 10 to 30 parts by weight based on 100total parts by weight of the composition. The cross-linked SAN can bepresent in compositions of the invention in amounts which rangegenerally from 0.25 to about 4.0, desirably from about 0.50 to about2.5, and preferably from about 0.75 to about 2.0 parts by weight basedon 100 total parts by weight of the composition. High molecular weightSAN can be present in compositions of the invention in amounts whichrange generally from about 0.1 to about 20, desirably from about 0.1 toabout 10 and preferably from about 0.1 to 8 parts by weight based on 100total parts by weight of the composition.

Suitable grades of SAN are commercially available from sources suchStyrolution as LURAN® 358N, LURAN®-VLN, and LURAN®-VLR and GalataChemicals as Blendex® 869, Blendex® 5215, Blendex® 5233, and Blendex®BMAT.

In one preferred embodiment, the compositions of the present inventioninclude two or more, three or more, four more different grades or typesof SAN. In one preferred embodiment, the compositions include SAN,cross-linked SAN, and high molecular weight SAN.

Optional Additives

The compositions of the present invention can also include additives,each in a sufficient amount to obtain alone or in combination with othercomponents, a desired property of the composition. Such additives arewell known to those of ordinary skill in the art and are described invarious references regarding polymeric materials, e.g. Modern PlasticsHandbook and Additives for Plastic Handbook. Examples of variousadditives that can be included in compositions of the present inventioninclude, but are not limited to, colorants, pigments, plasticizers,lubricants, UV stabilizers, light stabilizers, thermal stabilizers,antioxidants, antistatic agents, flame retardants, fillers, fibers,processing aids, biocides, surfactants, blowing agents, foaming agents,waxes and combinations thereof.

The additives can be utilized in various amounts to impart a desiredproperty to the composition. Thus, ranges of individual additives withina composition can vary.

Composition Form and Processing

The compositions of the present invention are generally prepared bycompounding or blending the desired components in one or more steps,preferably by mixing. The composition is preferably heated to obtain amelted composition, preferably with mixing, to substantially dispersethe components thereof, as desired. The blending is preferably performedat a temperature below the decomposition temperatures of the componentsand generally from about 140° C. to about 200° C. The compositions canbe prepared for example in a Banbury, on a two roll mill, in acontinuous mixer such as single screw or twin screw extruder, a kneader,or any other mixing machine as known to those of ordinary skill in theart. After preparation of the compositions, they can be processed intoany desired form. For example, the compositions can be of a form, suchas, but not limited to, a powder, pellet, strand, bead, etc., of variousshapes and sizes. Alternatively, the compositions can be directlymolded, or shaped as desired, for example using an extruder, injectionmolder, compression molder, calender, or the like.

Composition Features for capstock material are high abrasion resistance,excellent outdoor UV protection, high LOI, and good chemical stainresistance.

Uses/Composites

In some embodiments, the compositions of the present invention can beformed into a useful article, such as any of the articles mentionedherein.

Various composites can also be formed including at least one layer of acomposition of the present invention and at least a second layer. Thecomposite can be manufactured as articles including, but not limited to,decking, siding, fencing, frames, gutters, appliance housings, applianceliners, building materials, countertops, bathtubs, shower surroundmaterials, railings, shutters, and extruded profiles.

As illustrated in FIG. 1, one suitable use for the compositions of thepresent invention is as a capstock. FIG. 1 illustrates an article 10 inthe form of an article that can be used for wood-replacementapplications, for example decking, fencing, railing, siding, and thelike. Article 10 includes a substrate or core 12 and a capstock layer14. The core 12 can comprise any desired material, such as, but notlimited to, a polymeric material, cellulosic material, metallicmaterial, ceramic material or any combination thereof.

The substrate or core to which a composition of the present inventioncan be attached to form a composite is formed from any suitablematerial. Various thermoplastic resins are especially useful for makingbuilding products, but would benefit from a protective or capstock layerof the present invention, with examples including a halogen-containingpolymers such as PVC and chlorinated PVC;acrylonitrile-butadiene-styrene (ABS), polyolefins such as polyethyleneand polypropylene; polystyrene such as high impact polystyrene;polycarbonate, nylon; polyester; and combinations thereof. In variousembodiments the substrate may be foamed, for example foamed PVC, foamedABS, and other polymeric material.

Cellulosic materials include any plant matter, for example wood andvarious plant fibers, such as flax fiber.

The capstock layer 14 comprises a composition of the present invention.The core 12 can have dimensions that vary according to the end use.Typical dimensions are those such as of wood boards utilized fordecking, fencing, siding, railing or the like. The capstock layer 14 isa relatively thin coating layer than may have a thickness generallybetween about 0.38 to about 1.27 mm, desirably from about 0.51 to about1.14 mm and preferably from about 0.64 to about 1.02 mm. The capstocklayer is present on at least one surface of the article 10. Asillustrated in FIG. 1, the capstock layer 14 covers three sides of thecore 12 in one embodiment. If desired, all four sides could be coatedwith a capstock layer. Likewise, the core in some embodiments may havemore than six sides that are coated in some embodiments.

The composition of the present invention can be bonded to a substrate orcore layer to form a composite by various methods. For example, acapstock layer can be bonded to the substrate with an adhesive. In otherembodiments the capstock layer and substrate layer are laminated orco-extruded to bond the capstock and substrate layers together. It is tobe understood that the present invention is not limited to anyparticular method of making the composite article or product.

In a preferred embodiment, a composition of the present and a substratelayer adhere to each other and are materials which are compatible and/ormiscible with one another. If desired, various surface treatments can beutilized to promote adhesion. Alternatively or in concert therewith, anadhesive can be utilized to adhere various layers of materials utilizedto form a composite including or having a layer comprising a compositionof the present invention.

For the avoidance of doubt, the compositions of the present inventionencompass all possible combinations of the components, including variousranges of said components, disclosed herein. It is further noted thatthe term ‘comprising’ does not exclude the presence of other elements.However, it is also to be understood that a description on a productcomprising certain components also discloses a product consisting ofthese components. Similarly, it is also to be understood that adescription on a process comprising certain steps also discloses aprocess consisting of these steps.

EXAMPLES

The examples set forth below are provided to illustrate the compositionsof the present invention. These examples are not intended to limit thescope of the invention.

All of the materials before melt mixing were pre-mixed to asubstantially free flowing state and were melt mixed with a Farrel Corpbanbury batch mixer. The fluxed batch was dropped and probed with aninternal batch temperature between 166° C.-188° C. The fluxed batch wasthen placed through a two roll which was annealed and prepared into amill sheet. The mill sheet was cut into strips and run through a dicer.The diced pellets were then run through a two roll mill where anothermill sheet was prepared. A portion of this mill sheet was then used forthe chemical stain testing. The remainder of the mill sheets were thenused to compression mold test plaques using a steam heated press forhardness, oxygen index, and abrasion testing.

The following raw materials were utilized for the examples.

PVC Oxy 216S from OXY VINYLS LP TPU Texin DP7-3041 from Bayer MaterialScience LLC ASA Royaltuf 960A from Galata Chemicals LLC SAN #1 Blendex5215 from Galata Chemicals LLC SAN #2 Blendex BMAT from Galata ChemicalsLLC SAN #3 Blendex 869 from Galata Chemicals LLC Antimony OxideBRIGHTSUN HB from Albermarle Corporation Calcium Stearate COAD 10 fromHM ROYAL INC PE Wax Polyethylene AC 629A from Honeywell INC NJ EBS WaxAdvawax 280 from PMC Biogenix, INC Stearyl Stearate Struktol VSSE fromStruktol Co. Ester AO/UV Package from Teknor Apex Co. StabilizerREATINOR RT4472 from Reagens USA INC Pigment CI Yellow 164 from TheShepherd Color Company

Following test protocols were used for testing:

Hardness Shore D ASTM D-2240 Oxygen Index % ASTM D-2863 Taber Abrasion -H18 Weight loss (g) ASTM D-1044 Chemical Staining SPF Spray Subjectspecimen to each Gasoline chemical for 15 minutes and Goof Offsubjectively rate as chemical Denatured staining (whitening) occursAlcohol

TABLE 1 Comparative Examples Based on Individual Polymer ComponentsExample Comparative Comparative Comparative Example 1 Example 2 Example3 PVC 97.51 TPU 97.51 ASA 56.19 SAN#1 41.32 SAN#2 1.50 1.50 1.50 SAN#34.00 4.00 4.00 Antimyony Oxide 3.00 3.00 3.00 Calcium Stearate 0.30 0.300.30 PE Wax 0.05 0.05 0.05 EBS Wax 0.40 0.40 0.40 Stearyl Stearate 0.300.30 0.30 Ester AO/UV 0.85 0.85 0.85 Stabilizer 0.60 0.60 0.60 Pigment6.00 6.00 6.00 Total Parts (weight) 114.51 114.51 114.51 Hardness Hand D83 50 68 (10 second delay) Oxygen Index % 47.0% 19.5% 20.0% TaberAbrasion - Grams 0.13 0.11 0.24 H18 after lost 1,000 hours ChemicalStaining None Moderate Slight after SPF Spray Chemical Staining None V.Slight Slight after Gasoline Chemical Staining Slight Moderate Severeafter Goof Off Chemical Staining None Slight None after DenaturedAlcohol

Table 1 presents three comparative examples utilizing a single polymer.Comparative example 1 utilizes PVC which exhibits a high limiting oxygenindex and very good chemical stain resistance, but a high hardness andknown poor outdoor UV weather and environmental resistance exists.Comparative example 2 utilizes TPU which has a reduced hardness andimproved taber abrasion resistance over PVC but exhibits very poorchemical resistance. Comparative example 3 utilizes ASA which is knownto provide superior outdoor UV weather and environmental resistanceexhibits moderate chemical resistance but has a poor limiting oxygenindex and poor abrasion resistance.

TABLE 2 Comparative Examples Based on Polymer Blends and InventiveExample Example Comparative Comparative Comparative Inventive Example 4Example 5 Example 6 Example PVC 30.00 30.00 30.00 TPU 67.51 30.00 20.00ASA 38.91 38.91 27.38 SAN#1 28.60 28.60 20.13 SAN#2 1.50 1.50 1.50 1.50SAN#3 4.00 4.00 4.00 4.00 Antimyony Oxide 3.00 3.00 3.00 3.00 CalciumStearate 0.30 0.30 0.30 0.30 PE Wax 0.05 0.05 0.05 0.05 EBS Wax 0.400.40 0.40 0.40 Stearyl Stearate Ester 0.30 0.30 0.30 0.30 AO/UV 0.850.85 0.85 0.85 Stabilizer 0.60 0.60 0.60 0.60 Pigment 6.00 6.00 6.006.00 Total Parts (Weight) 114.51 114.51 114.51 114.51 Hardness Hand (10D 68 74 60 70 second delay) Oxygen Index % 21.5% 25.0% 21.0% 24.5% TaberAbrasion Grams 0.13 0.15 0.36 0.21 lost Chemical Staining after ModerateNone Moderate None SPF Spray Chemical Staining after None Slight SevereV. Slight Gasoline Chemical Staining after Slight Severe Severe SlightGoof Off Chemical Staining after V. Slight None Moderate None DenaturedAlcohol

Table 2 presents three comparative examples utilizing polymer blendswith either PVC/TPU, PVC/ASA, or ASA/TPU. Comparative example 4 utilizesPVC/TPU which exhibits a relatively low hardness, very low abrasionresistance, but a low LOI and poor chemical stain resistance.Comparative example 5 utilizes a PVC/ASA blend which has a higher LOIand low abrasion resistance, but has a relatively high hardness andsuffers severe staining after Goof Off chemical exposure. Comparativeexample 6 utilizes an ASA/TPU blend which provides improved hardness,but has poor chemical stain resistance, low LOI, and poor abrasionresistance. The inventive example utilizes a ternary blend comprisingPVC/ASA/TPU which has an overall balance of properties that aredesirable for capstock decking applications as well as other plasticparts. This inventive sample achieves desirable chemical stainresistance, higher LOI, good abrasion resistance, reduced hardness, andgood outdoor UV resistance.

While in accordance with the patent statutes the best mode and preferredembodiment have been set forth, the scope of the invention is notlimited thereto, but rather by the scope of the attached claims.

What is claimed is:
 1. A thermoplastic composition, comprising: a.) ahalogen-containing polymer; b.) a thermoplastic polyurethane; c.) atleast one acrylic polymer.
 2. The composition according to claim 1,wherein the halogen-containing polymer is a chlorine-containing polymer.3. The composition according to claim 2, wherein a plurality ofdifferent acrylic polymers are present and comprise one or more ofpolyacrylate-styrene-acrylonitrile copolymer, styrene-acrylonitrilecopolymer, cross-linked styrene-acrylonitrile copolymer, and a highmolecular weight styrene-acrylonitrile copolymer.
 4. The compositionaccording to claim 3, wherein the polyurethane is derived from acomposition including a polyether polyol, and wherein thehalogen-containing polymer comprises PVC.
 5. The composition accordingto claim 4, wherein the acrylic polymer includes at least apolyacrylate-styrene-acrylonitrile copolymer and a styrene-acrylonitrilecopolymer, wherein the polyacrylate-styrene-acrylonitrile copolymer ispresent in an amount from 15 to about 50 parts by weight, and whereinthe styrene-acrylonitrile copolymer is present in an amount from 10 toabout 40 parts by weight, based on 100 total parts by weight of thecomposition.
 6. The composition according to claim 5, wherein thecomposition further includes a cross-linked styrene-acrylonitrilecopolymer and a high molecular weight styrene-acrylonitrile copolymer.7. The composition according to claim 1, wherein the halogen-containingpolymer is a chlorine-containing polymer, wherein the acrylic polymerincludes at least a polyacrylate-styrene-acrylonitrile copolymer and astyrene-acrylonitrile copolymer, and wherein the composition furtherincludes a cross-linked styrene-acrylonitrile copolymer and a highmolecular weight styrene-acrylonitrile copolymer.
 8. The compositionaccording to claim 5, wherein the cross-linked styrene-acrylonitrilecopolymer is present in an amount from 0.25 to about 4.0 parts byweight, and wherein the high molecular weight styrene-acrylonitrilecopolymer is present in an amount from 0.1 to about 20 parts by weight,based on 100 total parts by weight of the composition.
 9. Thecomposition according to claim 1, wherein the halogen containing polymeris present in an amount from about 15 to about 60 parts by weight,wherein the thermoplastic polyurethane is present in an amount fromabout 1 to about 50 parts by weight, acrylic polymer comprises apolyacrylate-styrene-acrylonitrile copolymer present in an amount fromabout 10 to about 50 parts by weight, all said parts based on 100 totalparts by weight of the composition.
 10. The composition according toclaim 9, wherein the halogen containing polymer is present in an amountfrom about 20 to about 40 parts by weight, wherein the thermoplasticpolyurethane is present in an amount from about 1 to about 40 parts byweight, and wherein the polyacrylate-styrene-acrylonitrile copolymer ispresent in an amount from about 15 to about 50 parts by weight.
 11. Acapstock formed from the thermoplastic composition according to claim 1.12. An article comprising a substrate and a capstock layer attached tothe substrate, wherein the capstock layer comprises the thermoplasticcomposition according to claim
 1. 13. A composite article, comprising: acapstock layer, comprising: a halogen-containing polymer in an amountfrom about 15 to about 60 parts by weight; a thermoplastic polyurethanein an amount from about 10 to about 50 parts by weight; and at least oneacrylic polymer in an amount from about 10 to about 50 parts by weight,all said parts based on 100 total parts by weight of the composition;and a substrate layer comprising one or more of a polymeric material,cellulosic material, metallic material, and ceramic material, whereinthe capstock layer is attached to the substrate layer.
 14. Thecomposition according to claim 13, wherein the halogen-containingpolymer is a chlorine-containing polymer.
 15. The composition accordingto claim 14, wherein a plurality of different acrylic polymers arepresent and comprise one or more of polyacrylate-styrene-acrylonitrilecopolymer, styrene-acrylonitrile copolymer, cross-linkedstyrene-acrylonitrile copolymer, and a high molecular weightstyrene-acrylonitrile copolymer.
 16. The composition according to claim15, wherein the polyurethane is derived from a composition including apolyether polyol, and wherein the halogen-containing polymer comprisesPVC.
 17. The composition according to claim 16, wherein the acrylicpolymer includes at least a polyacrylate-styrene-acrylonitrile copolymerand a styrene-acrylonitrile copolymer, wherein thepolyacrylate-styrene-acrylonitrile copolymer is present in an amountfrom 15 to about 50 parts by weight, and wherein thestyrene-acrylonitrile copolymer is present in an amount from 10 to about40 parts by weight, based on 100 total parts by weight of thecomposition.
 18. The composition according to claim 13, wherein thehalogen-containing polymer is a chlorine-containing polymer, wherein theacrylic polymer includes at least a polyacrylate-styrene-acrylonitrilecopolymer and a styrene-acrylonitrile copolymer, and wherein thecomposition further includes a cross-linked styrene-acrylonitrilecopolymer and a high molecular weight styrene-acrylonitrile copolymer.19. The composition according to claim 13, wherein the capstock layerhas a thickness of about 0.38 to about 1.27 mm, and wherein the capstocklayer covers at least three sides of the substrate.
 20. A method forproducing the composite article according to claim 13, including thestep of laminating or co-extruding the capstock layer and the substratelayer.